Bat handle with optimal damping

ABSTRACT

A bat has an elongate tubular striking member of a first material, and an elongate handle member of a second material. The handle may be of composite material laid up in selected layers and orientation to produce selected weight distribution, strength, and stiffness and improved batting capabilities. The striking member and handle member may have juncture sections which are substantially rigidly interconnected through mating configurations.

RELATED U.S. APPLICATION DATA

The present invention is a continuation-in-part of U.S. patentapplication Ser. No. 10/833,747 entitled “Bat Having Flexible Handle”filed on Apr. 28, 2004 by Guenther et al., which is acontinuation-in-part of U.S. patent application Ser. No. 10/115,593,entitled “Bat With Composite Handle,” filed on Apr. 2, 2002 by Eggimanet al.

FIELD OF THE INVENTION

This invention relates to a ball bat, and more particularly to a ballbat with a striking barrel member made to provide desired strikingcapabilities, and a handle member made to provide desired swingingcapabilities.

BACKGROUND AND SUMMARY OF THE INVENTION

Tubular metallic baseball bats are well known in the art. A familiarexample is a tubular aluminum bat. Such bats have the advantage of agenerally good impact response, meaning that the bat effectivelytransfers power to a batted ball. This effective power transfer resultsin ball players achieving good distances with batted balls. Anadditional advantage is improved durability over crack-prone woodenbats.

Even though presently known bats perform well, there is a continuingquest for bats with better hitting capabilities. Accordingly, oneimportant need is to optimize the impact response of a bat. Further, itis important to provide a bat with proper weighting so that its swingweight is apportioned to provide an appropriate center of gravity andgood swing speed of impact components during use.

Generally speaking, bat performance may be a function of the weight ofthe bat, distribution of the weight, the size of the hitting area, theeffectiveness of force transfer between the handle and the strikingbarrel, and the impact response of the bat. The durability of a batrelates, at least in part, to its ability to resist denting or crackingand depends on the strength and stiffness of the striking portion of thebat. An attempt to increase the durability of the bat often produces anadverse effect on the bat's performance, as by possibly increasing itsoverall weight and stiffness, or having less than optimum weightdistribution.

It has been discovered that a hitter often can increase bat speed byusing a lighter bat, thereby increasing the force transferred to theball upon impact. Thus it would be advantageous to provide a bat havinga striking portion which has sufficient durability to withstand repeatedhitting, yet which has a reduced overall bat weight to permit increasedbat speed through use of an overall lighter weight bat.

It also has been discovered that greater hitting, or slugging,capability may be obtained by providing a bat with a handle made of amaterial different from the material of the striking portion or formedin such a manner as to have different capabilities. One manner forproviding such is to produce a bat with a composite handle, wherein thecomposite material may be structured to provide selected degrees offlexibility, stiffness, and strength. For example, in one hittingsituation it may be best to have a bat with a more flexible handle,whereas for other hitting situations it is advantageous to have a handlewith greater stiffness.

An example of a prior attempt to provide a bat with a handle connectedto a barrel section is shown in U.S. Pat. No. 5,593,158 entitled “ShockAttenuating Ball Bat.” In this patent an attempt was made to produce abat with handle and barrel member separated by an elastomeric isolationunion for reducing shock (energy) transmission from the barrel to thehandle, and, inherently from the handle to the barrel. Accordingly, sucha design does not allow for maximum energy transfer from the handle tothe barrel during hitting. As a result, the bat produces less energytransfer or impact energy to the ball due to the elastomericinterconnection between the handle and barrel.

Therefore there is a continuing need for a bat that provides theflexibility of a separate handle member and striking member andmaximizes the energy transfer between the two members. A continuing needalso exists for a ball bat that provides exceptional feel and controlwithout negatively affecting slugging or hitting performance.

The present invention provides an improved bat with a striking portionwith good durability and striking capabilities and a handle portion withdesirable weight and stiffness characteristics to permit greater batspeed during hitting.

One embodiment of the invention provides a bat having an elongatetubular striking member with a juncture section which converges inwardlytoward the longitudinal axis of the bat on progressing toward an end ofthe striking member, and an elongate handle member having an end portionthereof which is firmly joined to the converging end portion of thestriking member to provide a rigid interconnection therebetween topermit substantially complete striking energy transfer between thehandle member and the striking member.

In another embodiment, the bat has an elongate tubular striking memberhaving a juncture section adjacent its proximal end, the striking memberbeing composed of metal having a first effective mass, and an elongatehandle member composed of a material having a second effective masswhich is less than the first effective mass of the striking member, thehandle member having a juncture section adjacent its distal end, withthe juncture sections of the striking member and handle memberoverlapping and being joined together to provide a rigid interconnectiontherebetween to permit substantially complete striking energy transferbetween the striking member and the handle member on hitting. Becausethe handle member is of a lower effective mass it will help to produce alighter weight bat with the possibility of a greater swing speed.

The present invention provides a novel bat and method for producing thesame wherein the striking portion is comprised of the most appropriate,or optimum, structure for striking and the handle is comprised of themost appropriate, or optimum, structure for swinging, and the two arejoined for optimum slugging capability.

The present invention provides a bat, and method for making a bat,wherein selected materials are used in selected portions of the bat toachieve proper weight, or mass, distribution for optimum swing speed andto provide desired strength, stiffness and damping of selected portions.

According to a principal aspect of a preferred form of the invention, abat has a longitudinal axis and an overall first length, and is capableof being tested with a three-point bend stiffness test device havingfirst and second supports. The bat includes an elongate tubular strikingmember and a separate handle member. The striking member has a distalend, a proximal end, and a striking region intermediate the distal andproximal ends. The handle member has a distal end and a proximal end,and is coupled to the striking member. The handle member has aresistance to bending along the longitudinal axis of the bat in therange of 10-1000 lbs/in a three-point bend stiffness test wherein thehandle member is transversely supported in a first direction by thefirst and second supports spaced apart a selected distance, with thefirst support adjacent the distal end and the second support adjacentthe proximal end, and the handle member is transversely loaded in asecond direction, opposite the first direction, at a location on thehandle member in a region between 30% and 40% of the selected distancefrom the distal end of the handle member.

According to another principal aspect of the present invention, a bathas a longitudinal axis, and is capable of being tested with athree-point bend stiffness test device having first and second supports.The bat includes a non-wooden, one-piece bat frame. The frame includes adistal end, a proximal end, an elongate tubular striking portion, and ahandle portion. Either the handle portion or the striking portionincludes a tapered region. The frame has a resistance to bending alongthe longitudinal axis in the range of 10-950 lbs/in a three-point bendstiffness test wherein the frame is transversely supported in a firstdirection by the first and second supports, wherein the first support ispositioned at a first predetermined position, wherein the firstpredetermined position being the location where the tapered region has afirst predetermined outer diameter, wherein the second supportpositioned a first predetermined distance from the first predeterminedposition, and wherein the frame is transversely loaded in a seconddirection, opposite the first direction, on the handle member at asecond predetermined position that is located on the handle portion asecond predetermined distance from the first predetermined position. Thesecond predetermined distance is between 30% and 40% of the firstpredetermined distance.

According to another principal aspect of the present invention, a methodof categorizing a plurality ball bats includes the following steps. Atleast two distinct bat categories are created based upon at least onebat characteristic. The at least one bat characteristic includes eitherthe resistance to bending of the frame of the bat or the resistance tobending of the handle portion of the frame of the bat. The methodfurther includes determining the resistance to bending of one of theframe and the handle portion for the plurality of bats. The method alsoincludes assigning one of the at least two categories to each of theplurality of bats based, at least in part, upon either the resistance tobending of the frame or the resistance to bending of the handle portion.

The present invention contemplates producing a handle member withmultiple composite layers which are appropriately oriented and joined toprovide a handle which has selected strength and stiffness. By providinga bat with a handle member made of composite material which may be laidup in multiple layers with selected orientation and strength, the handlemember may be structured to provide selected degrees of strength,flexibility, and vibration transfer in an assembled bat. The presentinvention also contemplates producing a handle member of a thermoplasticmaterial.

In one embodiment, one of the juncture sections of the striking memberor the juncture section of the handle member has projections thereonwhich extend radially from remainder portions of the juncture section adistance substantially equal to the thickness of a desired layer ofadhesive to join the striking member and handle member. Such projectionsfirmly engage the facing surface of the other member and this, inconjunction with the adhesive applied between the two members, providesa firm interconnection therebetween.

According to another principal aspect of the present invention, a bat iscapable of being tested with a modal analysis test assembly having firstand second supports assemblies. The bat includes an elongate tubularstriking member and a separate handle member. The striking member has adistal end, a proximal end, and a striking region intermediate thedistal and proximal ends. The handle member has a distal end and aproximal end. The handle member is coupled to the striking member, andis formed of a thermoplastic or fiber-reinforced thermoplastic material.The handle member has a damping ratio in the first bending mode ofgreater than or equal to 0.010 in a modal analysis test wherein thehandle member is supported by the first support assembly adjacent thedistal end of the handle member and the second support assembly adjacentthe proximal end of the handle member. The bat is configured fororganized, competitive play.

According to another principal aspect of the present invention, a batcapable of being tested with a modal analysis test assembly having firstand second supports assemblies. The bat includes a non-wooden, one-piecebat frame. The bat frame includes a distal end, a proximal end, anelongate tubular striking portion and a handle portion. The handleportion includes a tapered region and the handle portion is formed of athermoplastic or fiber-reinforced thermoplastic material, The handleportion has a damping ratio in the first bending mode of greater than orequal to 0.010 in a modal analysis test wherein the handle portion iscut away from the striking portion at a first location, and wherein thehandle portion is supported by the first support assembly adjacent theproximal end of the bat frame and the second support assembly at thetapered region of the handle portion. The first location occurs wherethe tapered region of the handle portion has an outer diameter withinthe range of 1.9 to 2.25 inches. The bat is configured for organized,competitive play.

According to another principal aspect of the present invention, a bat iscapable of being tested with a modal analysis test assembly having firstand second supports assemblies. The bat includes an elongate tubularstriking member and a separate handle member. The striking member has adistal end, a proximal end, and a striking region intermediate thedistal and proximal ends. The handle member has a distal end and aproximal end. The handle member is coupled to the striking member. Thehandle member has first and second damping ratios in the first andsecond bending modes, respectively, of greater than or equal to 0.020 ina modal analysis test wherein the handle member is supported by thefirst support assembly adjacent the distal end of the handle member andthe second support assembly adjacent the proximal end of the handlemember. The handle member also has a first bending mode frequency ofgreater than or equal to 100 Hz and less than or equal to 280, and asecond bending mode frequency of greater than or equal to 450 and lessthan or equal to 1000 Hz. The handle member has a resistance to bendingalong a longitudinal axis in the range of 10-850 lbs/in a three-pointbend stiffness test wherein the handle member is transversely supportedin a first direction by the first and second supports spaced apart aselected distance. The first support is positioned adjacent the distalend of the handle member and the second support is positioned adjacentthe proximal end of the handle member, and the handle member istransversely loaded in a second direction, opposite the first direction,at a location on the handle member in a region between 30% and 40% ofthe selected distance from the distal end of the handle member. The batis configured for organized, competitive play.

This invention will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingdrawings described herein below, and wherein like reference numeralsrefer to like parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view through the longitudinal center of a bat inaccordance with one embodiment of the invention.

FIG. 2 is a magnified sectional view of a juncture section of the bat ofFIG. 1.

FIG. 3 is a cross sectional view taken generally along the line 3-3 inFIG. 2.

FIG. 4 is a view taken generally along the line 4-4 in FIG. 2, with aportion of the striking member broken away.

FIG. 5 is a view similar to FIG. 4, but with a different ribconfiguration.

FIG. 6 is a magnified sectional view of a portion of the handle takengenerally along the line 6-6 in FIG. 2.

FIGS. 7-9 are perspective views of a flared end portion of the handlewith forming members associated therewith during the production of thehandle member to produce projecting ribs on the juncture section of thehandle.

FIG. 10 is an enlarged longitudinal cross section of a handle member asmay be used in the bat of FIG. 1, with portions broken away toillustrate composite lay up of the handle member with multiple compositematerial layers disposed at various regions along the length of thehandle and with some sections of the handle having more layers thanothers and being composed of different materials to obtain selectedhandle member mass, strength and stiffness characteristics.

FIG. 11 is a side elevation view of a test fixture for testing thebending strength of a handle member with an exemplary handle membermounted therein for testing.

FIG. 12 is a side elevation view of a test fixture for testing thebending strength of a full length assembled bat with an exemplary handlemember mounted therein for testing.

FIG. 13 is a side view of a bat having a one-piece integral frame.

FIG. 14 is a side elevation view of a test fixture for testing thebending strength of a bat with an exemplary assembled bat, or a bathaving a one-piece integral frame, mounted therein for testing.

FIG. 15 is a side elevation view of a test fixture for testing thefrequency and damping ratio of a handle portion of a bat.

FIG. 16 is a table illustrating bat handle excitation data in afrequency domain.

FIG. 17 is a table illustrating a first bending mode shape of a handlemember including frequency and damping.

FIG. 18 is a table illustrating a second bending mode shape of a handlemember including frequency and damping.

DETAILED DESCRIPTION

Referring to FIG. 1, an elongate tubular ball bat 10 having alongitudinal axis, or centerline, 20 comprises an elongate tubularstriking member 12. The striking member has a proximal, or inner, end 12a and a distal, or outer, end 12 b. A striking region 14 is disposedintermediate ends 12 a, 12 b. A frusto-conical juncture section 16 ofthe striking member adjacent end 12 a converges toward centerline 20 onprogressing toward end 12 a.

In the embodiment illustrated in FIGS. 1 and 2 striking region 14 has asubstantially cylindrical inner cavity, with an inner diameter D₁. Acylindrical tubular insert 22 is received in the striking region cavityto form a multiple-wall bat. The insert has proximal, or inner, anddistal, or outer, ends 22 a, 22 b, respectively. End 22 a is disposedadjacent juncture section 16. The bat also could be made as asingle-wall bat without insert 22.

Juncture section 16 has a major diameter equal to D₁ and a minordiameter noted D₂ at its end 12 a.

An elongate tubular handle member 30 is secured to and projectslongitudinally outwardly from end 12 a and juncture section 16 of thestriking member.

The assembled bat 10 has an overall length L₁. Striking member 12 has alength L₂ and handle member 30 has a length L₃. As seen lengths L₂ andL₃ are each substantially less than L₁.

The handle member 30 in the illustrated embodiment may be made of acomposite material or other appropriate material as will be discussed ingreater detail below. It has opposed distal, or outer, end 30 a, andproximal, or inner, end 30 b. The handle member has an elongate, hollow,tubular, substantially cylindrical gripping portion 32 of a diameter D₃throughout a major portion of its length, and a frusto-conical juncturesection 34 adjacent end 30 a. As best seen in FIGS. 1 and 2, juncturesection 34 diverges outwardly from the longitudinal axis in aconfiguration complementary to the converging portion of juncturesection 16 of the striking member. Juncture section 34 has a minordiameter D₃ (less than D₂), a major diameter D₄ (greater than D₂, butless than D₁), and a length which is no greater than 25% of the overalllength L, of the assembled bat.

End 12 a of striking member 12 provides an opening with a diameter D₂greater than diameter D₃ of gripping portion 32 of handle member 30. Thediverging portion of juncture section 34 of the handle member is suchthat the outer surface of juncture section 34 is substantiallycomplementary to the configuration of the inner surface of juncturesection 16 of the striking member so that they may fit in close contactwith each other when assembled as illustrated in FIGS. 1 and 2.

Referring to FIGS. 3 and 4, it will be seen that juncture section 34 ofthe handle member in the illustrated embodiment has a plurality ofelongate, radially extending ribs, or projections, 40 on its outersurface. These ribs extend substantially longitudinally of the handlemember, and are spaced apart circumferentially substantially equallyabout juncture section 34, or at approximately 120 from each other asillustrated.

Projections, or ribs, 40 extend outwardly from remainder portions of thejuncture section of the handle member a distance substantially equal tothe thickness of a layer of adhesive which it is desired to applybetween juncture section 16 of the striking member and juncture section34 of the handle member to secure these two members together to form thecompleted bat. It has been found desirable to apply a layer of adhesivebetween the juncture sections of the handle member and the strikingmember, which is in a range of 0.001 to 0.010 inch thick, and preferablywithin a range of 0.002 to 0.005 inch thick. Thus ribs 40 projectoutwardly from remainder portions of juncture section 34 a distance in arange of 0.001 to 0.010 inch and more preferably in a range of 0.002 to0.005 inch.

When assembled as illustrated in the drawings, the outer surfaces ofprojections 40 firmly engage the inner surface of juncture section 16 ofthe striking member, with a layer of adhesive filling the space betweenthe circumferentially spaced ribs, or projections, to adhesively jointhe striking member to the handle member in this juncture section. Alayer of such adhesive is indicated generally at 42.

Although projections 40 are shown as formed on the handle, it should berecognized that projections formed on the inner surface of the juncturesection of the striking member and extending radially inwardly fromremainder portions of the striking member could be used also.

FIG. 4 illustrates an embodiment of the invention in which the ribs 40are substantially straight, and extend longitudinally of the handlemember. FIG. 5 illustrates another embodiment in which the ribs 46 arecurved, such that they extend somewhat helically about the outer surfaceof juncture section 34. They function similarly to ribs 40.

Although the projections, which may be formed on the external surface ofthe juncture section of the handle or on the internal surface of thejuncture section of the striking member, have been illustrated anddescribed generally as elongate ribs, it should be recognized that thepurpose of such projections is to provide a firm contacting engagementbetween the juncture section portions of the handle member and strikingmember to produce a substantially rigid interconnection therebetween.Thus, the projections do not necessarily have to be elongate ribs asillustrated. Instead, there could be a plurality of projections ofsubstantially any shape extending outwardly from remainder portions ofthe juncture section of the handle member or projecting inwardly fromthe inner surface of the juncture section of the striking member, or anycombination thereof, such that firm interengagement is provided betweenthe striking member and the handle member. For example the projectionsmay be a pebbled surface configuration, criss-crossed ribs, irregularlyshaped ribs, or any other configuration that provides a plurality ofraised surfaces for direct contact with the other member to provide asubstantially rigid interconnection between the handle member and thestriking member.

The complementary converging and diverging configurations of thejuncture sections of the striking member and handle member prevent thetwo parts from being pulled apart longitudinally in opposite directions,such as by pulling outwardly on opposite ends of the bat. The adhesiveis provided to inhibit longitudinal movement of the handle member andstriking member upon application of forces thereagainst such as mightoccur if forces were exerted at opposite ends of the bat in an attemptto compress them toward each other.

Although adhesive has been noted as a means for securing the two membersagainst relative longitudinal movement in the one direction, it shouldbe recognized that other means could be used also. For example,mechanical locking means of various types could be employed. Althoughnot shown herein, the striking member or handle member could be formedwith a radially projecting lip which engages a portion on the othermember when the parts are moved into the positions illustrated in FIGS.1-4 to prevent longitudinal separation of the members.

Further, although it has been mentioned that adhesive can fill thespaces between the projections, it is not necessary that the spacesbetween the projections always be filled, and a less than fillingquantity of adhesive may be adequate.

When assembled as illustrated in the drawings, juncture section 34 ofthe handle member fits tightly within juncture section 16 of thestriking member and a layer of adhesive interposed therebetween rigidlyinterconnects the striking member and handle member.

In a particularly preferred embodiment, the striking member 12 is aone-piece integrally formed generally tubular member, and the handlemember 30 is a one-piece integrally formed tubular unit. The strikingand handle members 12 and 30 are preferably coupled together through adirect connection to each other such that at least a portion of thestriking member 12 directly contacts at least a portion of the handlemember 30. A non-metallic substance (an adhesive) is also preferablydisposed between the handle and striking members 12 and 30 to furthersecure the connection between the handle and striking members.

In other alternative preferred embodiments, the handle and strikingmembers can be coupled together in a manner that prevents direct contactbetween the handle and striking members. In such alternative preferredembodiments, a non-metallic substance can be used to couple the handlemember to the striking member. The non-metallic substance can be anadhesive, an elastomer, an epoxy, a chemical bonding agent orcombinations thereof. In other alternative preferred embodiments, othertypes of conventional fastening or coupling means, such as, for example,metallic fasteners, one or more metallic or non-metallic tubularcoupling members and one or more rings, can be used to couple the handleand striking members. Further, because direct contact between the handleand striking members is not necessarily present in these alternativepreferred embodiments, the juncture sections each of the handle andstriking members can be formed with or without ribs or otherprojections.

The fully assembled bat as shown in FIG. 1 includes a knob 48 secured tothe proximal end 30 b of the handle member and a plug 50 inserted in andclosing the distal end 12 b of the striking member. Referring to FIG. 1,a weighted member, or plug, 54 is inserted and secured in the proximalend portion of handle member 30. The structure and function of member 54will be described in greater detail below.

A generally cylindrical transition sleeve 52 having a somewhatwedge-shaped cross section as illustrated in FIG. 2 is secured to handlemember 30 to abut end 12 a of the striking member to produce a smoothtransition between end 12 a of the striking member and the outer surfaceof handle member 30. Rather than applying a transition sleeve 52, theproximal end 12 a of juncture section 16 of the striking member may beswaged to a gradually thinner edge region with a rounded proximal edge.

Describing a method by which the bat illustrated in the figures may beproduced, striking member 14 is formed of a material and in a manner toprovide desired impact, or striking capabilities. The striking membermay be formed by swaging from aluminum tube (or other metal foundappropriate for the striking region of a bat) to yield an integralweld-free member. While swaging is one means of producing such strikingmember, it should be understood that other methods of manufacturingmight work equally as well.

The striking member is formed with a circular cross section having astriking region which has a cylindrical interior surface defining aninterior cavity of a first selected cross sectional dimension, ordiameter, D₁. This produces a striking member having a first effectivemass. The effective mass may be a function of the specific gravity ofthe material, size, thickness, or other characteristics.

The juncture section 16 converges inwardly toward longitudinal axis 20to an opening at end 12 a having an internal diameter indicated D₂ whichis less than D₁.

Insert 22 has an outer diameter corresponding generally to, but possiblyslightly smaller than, D₁ such that it may be inserted into the strikingportion 14 of striking member 12. Its proximal, or inner, end 22 a mayengage the beginning of the inward converging portion of juncturesection 16 which prevents the insert from shifting further toward end 12a of the striking member. End 12 b of the striking member 12 is bentover to form a circular lip with a bore extending therethrough. An endplug 50 is placed in the end of the bat to engage end 22 b of the insertto hold it in place.

The striking member 12 may be formed of tubular metal material of afirst specific gravity, which may be, but is not limited to, aluminum,steel, titanium, or other suitable metal material. The striking memberalso might be formed of composite or other suitable materials. Insert 22also may be made of any such tubular metal or a composite. The insertserves a function as set out in prior U.S. Pat. Nos. 5,415,398 and6,251,034. Since the striking member is formed separately from thehandle member, the striking member may be formed in such a manner andfrom such materials as to produce the desired, or optimum, impact, orstriking capabilities. Thus the requirements of the striking member andhandle member are decoupled permitting each to be made of such materialsand in such a manner as to provide optimum point location of mass in thebat and optimum strength and stiffness or flexibility where needed.

The handle member may be formed from material, which produces adifferent, and generally a lower, effective mass than it would have ifcomposed in a manner or of a material similar to that from which thestriking member is formed. The different effective mass of the handlemember may be a function of the specific gravity of the material formingthe striking member, its size, thickness or other characteristics. Forexample the material of the handle member may have a different specificgravity than the material from which the striking member is formed. Inone preferred embodiment, the handle member is formed of a thermoplasticmaterial, a fiber reinforced thermoplastic and combinations thereof.Some examples of thermoplastic materials include nylon, urethane, ABS,polyvinylchloride and combinations thereof. The fiber reinforcedthermoplastic material can include fibers formed of fiberglass, aramid,carbon, Kevlar®, high molecular weight polyethylene in strand form, orother conventional fiber materials.

In some instances the handle member may be formed of a compositematerial, such as carbon fiber, having a second specific gravity lessthan the first specific gravity of the striking member. In otherinstances the handle member may be formed of materials or in such amanner as to provide one or more operational or functionalcharacteristics which differ from those which the handle member wouldhave if merely formed in the same manner of the same material as thestriking member. For example the handle may be formed from othermaterials such as titanium, aluminum, plastic or other appropriatematerial.

Referring to FIG. 6, in one embodiment the handle member includesmultiple tubular composite layers as indicated generally at 60-66. Thelayers 60-66 are disposed adjacent each other and are arranged in asubstantially concentric manner. The number of layers must be sufficientto withstand the swinging action of the bat, a gripping force appliedthereto by a user, and the bending force imposed thereon when strikingwith the bat. However, preferably only the number of layers necessary towithstand such stresses would be provided, since more layers will addadditional weight to the handle member. The number, position, andorientation of the multiple layers will vary depending upon the size andtype of bat used. In one embodiment, the handle member may include theseven layers, 60-66, as shown. The number and thickness of layers andtheir position, and orientation may vary as needed to provide desiredflexibility or stiffness and to withstand gripping forces and hittingstresses.

Each composite layer in the embodiment illustrated includes structuralmaterial to provide structural stability and matrix material to supportthe structural material. The structural material may be a series offibers supported within the matrix material. In one preferredembodiment, most of the layers include fibers that preferably extendsubstantially longitudinally of the handle member. When the bat strikesa ball, the greatest stress component on the handle member may be inbending, thus the majority of the fibers preferably are directedlongitudinally to withstand these stresses. For example, the evennumbered layers 60, 62, 64, 66 may be longitudinally extending layers,whereas odd numbered layers 61, 63, 65, which are fewer in number, maybe circumferentially disposed layers. The longitudinally extendinglayers often are referred to as longitudinal, or 0 layers, since theyhave fibers that are directed substantially parallel to the longitudinalaxis. The other layers may be what are termed 90 layers, orcircumferential layers, since they have fibers, in which the majoritythereof is directed at substantially 90 relative to the longitudinalaxis. Specific layers may be constructed with fibers directed atsubstantially 90 relative to the longitudinal axis and other fibersdirected at substantially 0 and woven together within each layer. Or thelayers may be uni-directional layers wherein the fibers within thelayers are parallel.

In another preferred embodiment, one or more of the multiple tubularcomposite layers 60-66 can formed primarily of fibers extending in anon-longitudinal direction, with only a small percentage, or none, ofthe fibers extending in a longitudinal direction. In this preferredembodiment, the fibers can be laid substantially 90 from thelongitudinal axis, in various angled positions between 1-89, or incombinations thereof. By having a small percentage, or none, of thefibers extending at 0 (longitudinally), the stiffness of the handle canbe reduced and optimized to fit a particular application. In anotheralternative preferred embodiment, one or more of the multiple compositelayers can be formed of fibers, or fiber segments, in a random, orgenerally uniformly, configuration.

In this embodiment, the layers include carbon fibers. However the fiberscould be other type of known fiber material, such as, but not limitedto, Kevlar™, boron, aramid, fiberglass, or high molecular weightpolyethylene in strand form. A metallic mesh also might be used.

The matrix in the layers preferably is sufficiently durable and hassufficiently high adhesion properties to continue supporting thestructural material even after repeated use. In a preferred embodiment,the matrix material is a toughened epoxy. Alternatively, the matrix canbe some other thermally setting resin such as a polyester or vinylester. A person skilled in the art will appreciate that a thermoplasticresin can be used, rather than a thermally setting resin.

In particularly preferred embodiments, the handle member 30 has a weightof about 158 grams and is formed with the number of layers between 28 to40, wherein the weight of each layer varies from 0.6 to 14.0 grams. Atleast one layer of such embodiments is a braided layer having apercentage of the fibers within the braided layer extendinglongitudinally and the remaining fibers of the braided layer extendingsubstantially circumferentially. Also, from 1 to 4 layers are formedwith non-woven or non-braided fibers extending in two separatedirections, such as, for example, 0 degrees and 90 degrees.

Additionally, in particularly preferred embodiments, the handle member30 includes between 2 and 10 layers having longitudinally extendingfibers. In particularly preferred embodiments, the handle member 30includes a plurality of layers having helically extending fibers atvarious angles relative to the longitudinal axis, such as, for example,between 10 and 16 layers extend at plus or minus 30 degrees from thelongitudinal axis, between 6 and 16 layers extend at plus or minus 45degrees from the longitudinal axis, and 2 or less layers extend at plusor minus 60 degrees from the longitudinal axis.

Also, in particularly preferred embodiments, between 3 and 24 layers areformed of carbon fibers and between 13 and 25 layers are formed offiberglass fibers. The layers are formed in a variety of differentlengths varying from 5 cm to 67 cm. The layers, which are less than 67cm, are placed at varying positions along the full length of the handlemember. The layers are also formed in a variety of different widthsranging between 3.3 and 17.5 cm. Other layers have widths that varyalong their length from between 0 to 17.5 cm. The number of layershaving widths that vary along their length range between 8 and 11layers. The fibers within layers are formed with an area fiber densityof between 0.0143 and 0.048 grams/cm², and each layer can be formed witha weight in a range of 0.6 to 14 grams.

In alternative preferred embodiments, one or more of the characteristicsof the handle member can be altered, such as, for example: the weight,size, thickness and stiffness of the handle member; the number, size,composition and orientation of the layers; and the composition, density,and orientation of the fibers within a layer. The handle memberpreferably has a weight within a range of 3 to 8 ounces. The handlemember 30 can be formed without a braided layer or with an alternatenumber of braided layers. The handle member 30 can be formed with fiveor more layers of fibers wherein the non-woven fibers extend in twodirections or with no such layers. Two or more of the layers can includeother combinations of longitudinally, circumferentially and helicallyextending fibers. The handle member can be formed of multiple layershaving helically extending fibers wherein any one layer can have fibersextending between plus or minus 1 to 89 degrees from the longitudinalaxis. The fibers within the layers can be formed of other materials,such as, for example, glass, boron, graphite or other metal.

FIG. 10 is a simplified illustration of the manner in which multiplelayers of fiber composite material may be assembled. As is shown some ofthe layers extend the full length of the handle (layers 90 a, b, c, d),while others are shorter and reside in selected regions of the handlemember (90 e, f, g, h, i, j, k). Only a limited number of layers areshown in FIG. 10, for the sake of simplicity in the illustration.

The handle member includes a proximal gripping portion and a distaltapered portion, wherein one of the proximal gripping portion and thedistal tapered portion is formed with a larger number of layers than theremaining portion. The characteristics of the handle member thereforecan vary over its length.

The handle member 30, when formed of a composite material and producedin accordance with the present invention, can be produced with astiffness, or resistance to bending along the longitudinal axis 20 ofthe bat 10, within the range of 10 to 1980 lbs/in. when measured using atest method described below. In one preferred embodiment, the handlemember 30 is formed with a stiffness or resistance to bending within therange of 400-900 lbs/in. (The term “lbs/in.” refers to the amount offorce in pounds applied perpendicular to the member to produce on inchof deflection in a test method described below.)

In other alternative preferred embodiments, the handle member 30 isformed with a stiffness, or resistance to bending along the longitudinalaxis 20 of the bat 10, at specific levels within the range of 10 to 1980lbs/in. The inventors of the present invention have discovered that,contrary to conventional bat design and construction, when the handlemember 30 of the bat 10 is configured with a low stiffness, orresistance to bending along a longitudinal axis of the bat, the feel andperceived performance of the bat 10 significantly improves withoutnegatively affecting the reliability of the bat. The present inventioncontemplates multiple preferred embodiments of ball bats in which thestiffness, or a resistance to bending along the longitudinal axis of thebat, of the handle member 30 is significantly lower than conventionalbats. While conventional bat design focuses on bats having a resistanceto bending typically far above 1000 lbs/in. (often 2200-2500 lbs/in forconventional metallic bats), in order to prevent the bat from becoming“too whippy,” the present invention incorporates ball bats having handlemembers with significantly lower stiffness values (resistance to bendingalong the longitudinal axis of the bat), which are then tuned oroptimized to maximize the feel and performance of the ball bat for aparticular user.

Conventional performance bat design seeks to obtain a stiff handlemember or portion to be used in conjunction with a responsive strikingmember or portion. A responsive striking member or portion provides thedesired trampoline effect upon impact with a ball, and a stiff handlemember maximizes the mass and the force that can be applied ortransferred to the ball upon impact with the striking member or portion.A stiffer handle member or portion is also desired under conventionalbat design because it allows the batter to bring the head of the bataround for impact faster and in a more controlled manner.

Contrary to conventional performance bat design, the inventors of thepresent invention have discovered that producing a handle member, orportion, of a bat with a significantly lower resistance to bending in alongitudinal direction along the bat, provides the bat with asignificantly improved feel to the user, particularly during off-centerhits. Existing metallic and composite ball bats often provide painfulstinging or harsh vibrational feedback through the handle member orhandle portion of the bat to the user when the bat contacts the ballaway from the “sweet spot” of the striking member. This effect is oftenheightened at lower temperatures. A bat having a handle member, orportion, with a very low resistance to bending in the longitudinaldirection of the bat, however, significantly improves the feel of thebat by altering or reducing the size or configuration of the impactenergy extending along the bat. The handle member or handle portionhaving the low resistance to bending tends to isolate, alter and/orreduce the painful, harsh vibrational energy generated in a bat from anoff-center impact with a game ball.

Often, the harsh or painful sensation felt by a batter when impacting aball can have a significant negative impact on the ball player,particularly younger or less skilled players who do not always contactthe ball at the sweet spot of the striking member or portion. Manyplayers consciously, or subconsciously, alter or reduce the speed,motion or fluidity of their swing in an effort to avoid experiencing thestinging or harsh vibrational energy that can be generated upon impactwith a ball. The handle member or handle portion, having a significantlyreduced resistance to bending, alters, dampens, separates, isolatesand/or reduces this negative vibrational energy or sensation transmittedto the ball player, particularly during mis-hits. After repeated use ofsuch bats having a handle member or portion with a significantly lowerresistance to bending, the ball player experiences the improved feelprovided by the bat, particularly during mis-hits. The player typicallywill become more aggressive at the plate, swinging freer, smoother andoften faster, thereby often improving his or her performance, even whenmis-hitting the ball. Further, more skilled batters may be able toadjust their swings to maximize the impact of the significantly moreflexible handle members. More skilled players potentially can bring thebarrel or striking portion of the bat around into the point of impactwith a ball in a manner that takes advantage of the flexibility of thehandle to produce potentially greater bat head or striking portionspeed.

By lowering the resistance to bending of the handle member 30 wellbeyond the level of conventional bats, the present invention creates asignificantly broader range of bat configurations and provides theability to properly match a bat to a ball player. Other factors such asthe player's size, age, strength, skill level and swing speed, as wellas the type of ball game being played can be used along with theresistance to bending of the handle member to select a ball bat that isbest suited for an individual player. The present invention includes alarge number of bat configurations having resistance to bending levelsthat are significantly lower than conventional bats. In one particularlypreferred embodiment, the handle member has a resistance to bendingalong the longitudinal axis within the range of 900-1000 lbs/in. Inanother particularly preferred embodiment, the handle member has aresistance to bending along the longitudinal axis within the range of800-900 lbs/in. In another particularly preferred embodiment, the handlemember has a resistance to bending along the longitudinal axis withinthe range of 700-800 lbs/in. In other particularly preferredembodiments, the handle member can have a resistance to bending alongthe longitudinal axis within the ranges of 600-700 lbs/in., 500-600lbs/in., 400-500 lbs/in., 300-400 lbs/in., 200-300 lbs/in., 100-200lbs/in., 10-100 lbs/in., or combinations and variations of these ranges.Each one of these ranges, or variations of these ranges, can be used toprovide a bat having a resistance to bending that is best suited for aparticular ball player for a particular type of ball game. Each of theseranges or range variations can be used to produce an optimal bat for aparticular type of ball player for a particular application.

Referring to FIG. 11, the stiffness of the handle member 30 isdetermined through a three-point bend stiffness test wherein the handlemember is placed upon first and second supports 90 and 92 of a universaltest machine, or similar test machine, such as the universal testmachine produced by Tinius Olsen Testing Machine Co., Inc. of WillowGrove, Pa. The first support 90 is a V-block support positioned at thedistal end 30 a of the handle member 30. The V-block supportconfiguration of the first support 90 also serves to inhibit bothlongitudinal and transverse movement of the distal end 30 a of thehandle member 30. The second support 92 is a roller support including aroller 94 rotatable about a horizontal axis 96 spaced from V-blocksupport 90 and positioned near the proximal end 30 b of the handlemember 30. For handle members 30 greater than or equal to 19 inches, thesecond support 92 is positioned a distance D₆ of 19 inches from support90. The second support 92 also supports the handle member 30 in a firstdirection, preferably by maintaining the proximal end such that thelongitudinal axis 20 of the bat 10 is in a substantially horizontalposition. The second support 92 enables the proximal end 30 b to movelongitudinally.

The third point of the bend stiffness test is provided by a crosshead100, preferably having a semi-circular or circular shape. Mostpreferably, the semi-circular crosshead has a radius of 2.0 inches. Thecrosshead is configured to extend in a second direction opposite of thefirst direction. The crosshead may be moved downwardly onto thehorizontally positioned handle member 30 with a force noted F₁ imposedthereon. The crosshead is connected to a load cell (not shown) whichincludes a strain gauge for measuring the load applied to the crossheadduring displacement of the crosshead. The crosshead 100 is positioned adistance D₇ from the first support 90. Distance D₇ is in a range of 30%to 40% of distance D₆, and more preferably 7 inches, such that thesemicircular crosshead contacts the handle member at a locationapproximately 7.0 inches from the distal end 30 a of the handle member30.

During testing, the handle member is positioned as described above. Thecrosshead is driven in the second direction at a speed of 1.0 inches perminute. As the crosshead moves in the second direction (i.e., downwardlyin FIG. 12) the testing machine with input from the load cell calculatesthe load (F₁) per the lateral deflection, or displacement, of the handlemember 30.

Table 1 below illustrates the resistance to bending along thelongitudinal axis of a bat of handle members of an existing bat formedwith separate striking and handle members, as well as handle members ofbats formed under the present invention. TABLE 1 RESISTANCE TO BENDINGALONG A LONGITUDINAL AXIS FOR HANDLE MEMBERS OF BATS HAVING SEPARATEHANDLE AND STRIKING MEMBERS Resistance to Bending Test (lbs/in) Sample #Sample Description Test a Test b Average ts04-050 Easton ®Connexion ™/z-core 1559.20 1553.48 1556.34 titanium/−3 besr certified/34″/31 oz/mdl. bt7-z/baseball/ handle-barrel separated ts04-060-1DeMarini ® Sample No. 1 18.79 18.21 18.50 ts04-060 DeMarini ® Sample No.2 25.94 24.97 25.45 ts04-049 DeMarini ® Sample No. 3 30.71 31.51 31.11ts04-049-1 DeMarini ® Sample No. 4 36.71 38.82 37.77 vxw DeMarini ®Sample No. 5 557.81 593.91 575.86 evo 1 DeMarini ® Sample No. 6 609.03627.56 618.30 sf2 1 DeMarini ® Sample No. 7 797.58 720.04 758.81handle-1 DeMarini ® Sample No. 8 1589.56 1530.03 1559.80Easton ® is a registered trademark of Jas. D. Easton, Inc. Connexion ™is a trademark of Easton Sports, Inc.

The DeMarini® Sample s 1-7 are examples of handle members of the presentinvention having resistance to bending values well below the handlemembers of existing bats, which are configured with separate strikingand handle members. The handle members having the reduced resistance tobending values provide the ball player with a significantly improvedfeel and perceived performance. DeMarini Sample 1 has a resistance tobending value that is over 95% lower than the resistance to bending ofthe handle member of the existing Easton® Co nnexion™ bat model of Table1.

The bat 10 of the present invention can be formed with separate strikingand handle members 12 and 30 (see FIGS. 1-5) or as a bat 110 having anintegral one-piece frame 110 as shown in FIG. 13. The frame 110 includesa striking portion 112 integrally connected with the handle portion 114.The frame 110 is formed of a strong, flexible material, preferably acomposite material. Alternatively, other materials can be used, such as,for example, a tubular metal material or a combination of composite andmetal materials. Through the use of composite materials throughout theframe 110, the frame 110 can be designed with different characteristicsin the striking portion 112 compared to the handle portion 114.Preferably, the handle portion 114 is configured to be significantlymore flexible than the striking portion 112.

Referring to FIG. 12, one method of performing the three-point bendstiffness test on an assembled bat is illustrated. When testing a batthe first support 92 is positioned such that a proximal side of thefirst support lies a distance D₈, which may be approximately 6 inches,from the distal end 12 b of the striking member 12, and the secondsupport 92 is positioned a distance D₉, which may be approximately 6inches, from the proximal end 30 b of the handle member 30. The distancebetween supports 90, 92 is noted at D₁₀ and the cross head is positioneda distance D₁₀ from support 92, which is approximately one half D₁₀ soas to contact the bat at a point between and generally equidistant fromthe first and second supports.

During testing, the bat 10 is positioned as described above. Thecrosshead is driven in the second direction (downwardly in FIG. 12) at aspeed of 0.5 inches per minute. As the crosshead moves in the seconddirection, the testing machine with input from the load cell calculatesthe load per displacement of the bat.

Referring to FIG. 14, another method of performing the three-point bendstiffness test on an assembled bat is illustrated. The stiffness of thebat 10 (or 100) is determined through a three-point bend stiffness testwherein the handle member 30 (or handle portion 110) of the bat 10 (orbat 110) is placed upon the first and second supports 90 and 92 of theuniversal test machine, or similar test machine. The first support 90 isa V-block support positioned toward the distal end of the handle portion30 of the bat 10 and at the tapered region of the bat 10 (the taperedregion can be part of the handle portion, part of the striking portionor a combination of both portions). The tapered region of the bat 10 ismeasured to identify the location of a predetermined outside diameter ofthe bat 10. Preferably, an outside diameter of 2.1 inches is selected.Alternatively, an outside diameter within the range of 2.1 to 2.25inches can be selected. The tapered region of the bat 10 is placed intothe first support 90 at the location where the predetermined outsidediameter (preferably 2.1 inches) occurs. The V-block supportconfiguration of the first support 90 also serves to inhibit thetransverse movement of the bat 10.

The second support 92 is spaced from the V-block support 90 and ispositioned near the proximal end 30 b of the handle member 30. Thehandle member or portion is then placed over the second support 92. Thesecond support 92 is preferably positioned a distance D₆ of 19 inchesfrom support 90. The second support 92 also supports the handle member30 in a first direction, preferably by maintaining the proximal end suchthat the longitudinal axis 20 of the bat 10 is in a substantiallyhorizontal position. The second support 92 enables the proximal end 30 bto move longitudinally. If the bat 10 (or the bat 110) is configuredsuch that the handle member 30 (or the handle portion 110) of the bat 10(or the bat 110) does not extend to the second support 92, a differentpredetermined outside diameter value along the tapered region of the bat10, or the handle member 30, can be selected. A diameter greater than2.1 inches up to 2.25 inches can be used.

The third point of the bend stiffness test is provided by the crosshead100. The crosshead is configured to extend in the second directionopposite of the first direction. The crosshead may be moved downwardlyonto the horizontally positioned handle portion or handle member 30 witha force noted F₁ imposed thereon. The crosshead is connected to the loadcell (not shown) which includes the strain gauge for measuring the loadapplied to the crosshead during displacement of the crosshead. Thecrosshead 100 is positioned a distance D₇ from the first support 90.Distance D₇ is in a range of 30% to 40% of distance D₆, and morepreferably 7 inches, such that the semicircular crosshead contacts thehandle member at a location approximately 7.0 inches from the locationof the predetermined diameter (preferably 2.1 inches along the taperedregion of the bat 10).

During testing, the handle member is positioned as described above. Thecrosshead is driven in the second direction at a speed of 1.0 inches perminute. As the crosshead moves in the second direction (i.e., downwardlyin FIG. 13) the testing machine with input from the load cell calculatesthe load (F₁) per the lateral deflection, or displacement, of the handlemember 30.

The bat of the present invention can be formed such that the stiffnessof the bat 10 is within the range of 10 to 2500 lbs/in. In oneparticularly preferred embodiment, the bat 10 is formed with astiffness, or resistance to bending, within the range of 10 to 850lbs/in. In another preferred embodiment, the bat is formed with aresistance to bending within the range of 500 to 1500 lbs/in, and morepreferably in a range of 400-900 lbs/in. A conventional aluminum battypically has a stiffness, or resistance to bending, of approximately2200 to 2500 lbs/in. In one particularly preferred embodiment, the batis formed with a resistance to bending along the longitudinal axiswithin the range of 800-900 lbs/in. In another particularly preferredembodiment, the bat has a resistance to bending along the longitudinalaxis within the range of 700-800 lbs/in. In other particularly preferredembodiments, the bat can have a resistance to bending along thelongitudinal axis within the ranges of 600-700 lbs/in., 500-600 lbs/in.,400-500 lbs/in., 300-400 lbs/in., 200-300 lbs/in., 100-200 lbs/in.,10-100 lbs/in., or combinations and variations thereof. Each one ofthese ranges, or variations of these ranges, can be used to provide abat having a resistance to bending that is best suited for a particularball player for a particular type of ball game.

Table 2 provides a listing of the resistance to bending along thelongitudinal axis 20 of a number of existing ball bats and a number ofball bats configured under the present invention, measured using thesecond full (assembled) bat test method described above. (The term“lbs/in.” refers to the amount of force in pounds applied perpendicularto the bat to produce on inch of deflection in a test method describedbelow.) TABLE 2 RESISTANCE TO BENDING ALONG A LONGITUDINAL AXIS OFASSEMBLED BATS Resistance to Bending Test (lbs/in) Sample # SampleDescription Test a Test b Average ts04-032 Easton ®Connexion ™/−3/33″/30 oz/baseball 1413.79 1450.00 1431.90 ts04-033Worth ® supercell est/cryogenic/34″/27 oz/softball 1683.40 1689.931686.67 ts04-034 Easton ® z-core/−3/titanium/graphite reinforcedsc777/34″/31 oz/mdl.bz71-2/baseball 2320.11 2173.16 2246.64 ts04-035Worth ® 3dx/−3/34″/31 oz/model 3dxab/baseball 2166.02 2087.44 2126.73ts04-036 Easton ® Connexion ™/−3/32″/29 oz/baseball 1518.40 1565.501541.95 ts04-037 Baum ® aaa-pro/33″/33 oz/baseball 1895.87 1991.071943.47 ts04-038 Louisville Slugger ® TPX ™/gen1x/−3/33″/30 oz/modelcb203/baseball 2313.61 2299.33 2306.47 ts04-039 Easton ® z2k/-3/graphitereinforced sc500 scandium/mdl.bz2-kc/baseball 2707.45 2656.00 2681.72ts04-040 Easton ® (all aluminum)/youth baseball bat/31″ 1328.10 1323.591325.84 ts04-041 Easton ® Connexion ™ z-core/34″/26 oz/mdl.st1-2/softball 1111.51 1151.69 1131.60 ts04-042 Worth ® Wicked ™/34″/28ox/model wwsc/softball 1330.71 1375.98 1353.34 ts04-043 Easton ®synergy/34″ 28 oz/mdl. Scx2/softball 1005.63 992.40 999.02 ts04-044Louisville Slugger ® TPS/air attack 3/34″/28 oz/model sb22/softball1990.48 1891.51 1940.99 ts04-045 Louisville Slugger ® TPS/air c555/−10.5oz/34″/model fp25/fastpitch 1868.15 1835.37 1851.76 ts04-046 Mizuno ®techfire/victory stage/33″/model 2tp-50340/softball 2727.27 2780.902754.09 ts04-047 Easton ® cxn Connexion ™/sc888/29″/18.5 oz/mdl.lt8-z/youth baseball 1094.30 1183.22 1138.76 ts04-048 Easton ®Connexion ™/youth baseball bat/31″ 1128.07 1120.31 1124.19 ts04-004DeMarini ® Sample No. 9 306.44 306.40 306.42 ts03-191 DeMarini ® SampleNo. 10 529.59 464.58 497.08 ts03-040 DeMarini ® Sample No. 11 668.60674.12 671.36 wcb-32-1 DeMarini ® Sample No. 12 894.84 928.07 911.46wcb-33-1 DeMarini ® Sample No. 13 906.95 944.00 925.48 ts03-151DeMarini ® Sample No. 14 1176.81 1164.74 1170.78 ts03-107 DeMarini ®Sample No. 15 2347.97 2348.82 2348.40Easton ® is a registered trademark of Jas. D. Easton, Inc. Connexion ™is a trademark of Easton Sports, Inc. Worth ® is a registered trademarkof Worth, Inc. Wicked ™ is a trademark of Worth, Inc. Baum ® is aregistered# trademark of Baum Research & Development Company, Inc. LouisvilleSlugger ® is a registered trademark of Hillerich & Bradsby, Co. TPS ™and TPX ™ are trademarks of Hillerich & Bradsby, Co. Mizuno ® is aregistered trademark of Mizuno Corp.

Table 2 illustrates bats having different stiffnesses, or differentresistance to bending values, of a number of ball bats. Table 2 alsoillustrates the reduced resistance to bending of the bats of DeMariniSamples 9-13. The DeMarini Samples are configured in accordance with thepresent invention and provide for resistance to bending values that aresignificantly lower than those measured on existing ball bats. TheDeMarini Samples 1-7 and 9-13 of Tables 1 and 2 illustrate only a few ofthe variations in handle stiffness or resistance to bending contemplatedunder the present invention.

As stated above, the present invention enables the bat to be producedwith significantly less stiffness, greater flexibility, andsignificantly better feel to the player, without negatively affectingthe batting performance of the bat. The present invention enables one ofordinary skill in the art to vary the composition of the bat to producea bat that is optimally configured, adjusted or tuned to meet the needsof a particular player. The present invention also enables one ofordinary skill in the art to produce a bat that optimizes flexibilityand, through the direct connection between the handle member and thestriking member, maximizes energy transfer between the handle andstriking members, and the power output of the bat.

It should be noted that examples set out herein are only exemplary innature, and should not be considered limiting as to the structure andmethod of manufacture of bats according to the invention. For example,although the bat has been described with a metal striking member and acomposite handle member, such a wide difference in materials for the twomembers may not be necessary. For example, the striking member and thehandle member both may be made of composite material, but withconstructions which provide varying operational or functionalcharacteristics beneficial for the specific portion of the bat whichthey form.

The present invention also includes a method of categorizing a pluralityball bats or bat models (two or more) based, at least in part, upon thestiffness, or the resistance to bending of the bat along itslongitudinal axis. The method includes creating at least two distinctbat categories, or groupings of bats, based upon at least one batcharacteristic. The at least two bat categories or groupings of bats canbe two, three, four or more categories or groups. The at least one batcharacteristic includes at least the resistance to bending of the frameof the bat along the longitudinal axis of the bat, or the resistance tobending of the handle portion of the frame of the bat along thelongitudinal axis of the bat. Preferably, the at least one batcharacteristic used to create the two or more categories or groupings ofbats is two or more bat characteristics, wherein the secondcharacteristic is the weight of the bat, the length of the bat, theapplication the bat was configured for, the material of the handleportion of the bat, and the material of the frame of the bat. Furthercharacteristics of the ball player for which a particular bat isintended for also can be used. Such characteristics can include abatter's skill level, a batter's swing speed, a batter's experiencelevel, a batter's strength, a batter's age, and a batter's size. Stillfurther, the application for which the bat is intended for can also beused as one of the additional characteristics used to define thecategories.

The method also includes determining the resistance to bending of eitherthe frame or the handle portion for the plurality of bats, or batmodels. This resistance to bending along the longitudinal axis of thebat, or handle portion of the bat, can be accomplished through actualtesting or through use of design specifications. The method furtherincludes assigning one of the at least two categories to each of theplurality of bats based, at least in part, upon either the resistance tobending of the frame or the resistance to bending of the handle portion.The method of testing for the resistance to bending of the bat frame orthe handle portion of the frame is preferably accomplished using one ofthe three, three-point bend stiffness test approaches described above.Accordingly, the above-described method facilitates provided the batthat best fits a particular player. In other words, the bat can beflex-tuned to a particular player. For example, youth baseball bats maybe configured with handle portions having a lower resistance to bendingalong the longitudinal axis of the bat than adult baseball bats. Inother example, the youth baseball bats may be categorized with differentstiffness levels, or different levels of resistance to bending, in orderto appropriately match a bat to a particular youth player. One youthmodel would be stiff, the second less stiff, and the third even lessstiff, or more flexible.

Many embodiments of ball bats built in accordance with the presentapplication are specifically configured for providing optimumperformance in all levels of competitive, organized play. For example,many embodiments of ball bats built in accordance with the presentapplication fully meet the bat standards and/or requirements of one ormore of the following baseball and softball organizations: AmateurSoftball Association of America (“ASA”) Bat Testing and CertificationProgram Requirements (including the current ASA 2004 Bat Standard andthe ASA 2000.Bat Standard); United States Slo-Pitch Softball Association(“USSSA”) Bat Performance Standards for baseball and softball;International Softball Federation (“ISF”) Bat Certification Standards;National Softball Association (“NSA”) Bat Standards; IndependentSoftball Association (“ISA”) Bat Requirements; Ball Exit Speed Ratio(“BESR”) Certification Requirements of the National Federation of StateHigh School Associations (“NFHS”) and the National Collegiate AthleticAssociation (“NCAA”); Little League Baseball Bat Equipment EvaluationRequirements; PONY Baseball/Softball Bat Requirements; Babe Ruth LeagueBaseball Bat Requirements; and American Amateur Baseball Congress(“AABC”) Baseball Bat Requirements. Accordingly, the term “batconfigured for organized, competitive play” refers to a bat that fullymeets the ball bat standards and/or requirements of, and is fullyfunctional for play in, one or more of the above listed organizations.

In constructing the bat of the illustrated embodiment the strikingmember 12 may be formed as set out above. End 12 b initially remainscylindrical, without the bent over portion as illustrated in FIG. 1.

The tubular handle member may be formed by wrapping sheets ofpreimpregnated composite material on a mandrel. A first layer is wrappedon the mandrel, followed by a second layer, etc., until the desirednumber of layers have been wrapped on the mandrel in the desiredpositions and orientations to form the tubular handle member. Themandrel has a configuration which produces both the elongatesubstantially cylindrical gripping portion 32 and the divergingfrusto-conical juncture section 34.

To form projecting ribs 40, and referring to FIGS. 7-9, after asufficient number of layers of preimpregnated composite material havebeen wrapped onto the mandrel, a plurality of forming members indicatedgenerally at 70, 72, 74 having a selected arcuate configuration areplaced on the outside of the juncture section of the handle member whilethe composite material is still malleable. FIG. 7 shows members 70, 72,74 prior to placement on the outside of the juncture section 34 and theplacement of such is illustrated in dashed outline in FIG. 7. As is seenmembers 70, 72, 74 do not extend fully about the juncture section whenplaced thereon, but instead have gaps therebetween.

Members 70, 72, 74 have a thickness substantially equal to the desiredprojection for ribs 40 and the space between adjacent edges of elements70, 72, 74 is the desired width of ribs 40.

As mentioned previously, the projections may be in forms other thanelongate ribs and other molding or forming members may be provided toachieve the desired projection configurations.

When the forming members are placed against the juncture section asnoted, the tubular member then may be wrapped in shrink tape and placedin an oven between 250 and 300 F for about 45 minutes to one hour. Theshrink tape preferably is temperature resistant and has high shrinkageand compaction capability when heated. As the shrink tape contracts itpresses the composite layers into a desired configuration about theforming mandrel and presses members 70, 72, 74 into the compositematerial as seen in FIG. 8 to form depressions between areas whichbecome projecting ribs 40. The depressions are indicated generally at76, 78, 80, respectively, having a depth equal to the thickness ofmembers 70, 72, 74. FIG. 9 illustrates the configuration thus producedwhen members 70, 72, 74 are removed.

Heating the handle member speeds the curing process, but it may beallowed to cure at a lower temperature for a longer period of time. Forexample, the handle member may be allowed to cure at room temperaturefor several days. The pressure applied by the shrink tape may range from15 to 150 psi depending both on the type of the shrink tape used and theflow properties of the matrix material used. Alternately, some otherknown apparatus may be used to pressurize the handle member duringcuring, such as a bladder or a vacuum bag.

The handle member (or striking member if chosen to do so) also may beformed of a chopped fiber slurry. The chopped fibers can be carbon,glass, fiberglass, boron, or various metals.

Although not illustrated in the figures, it should be recognized thatother methods may be used for forming the handle and providing a desiredseries of projections thereon. One method of doing so is to wrap sheetsof pre-impregnated composite material onto a mandrel as previouslydescribed to form the general configuration for the handle with itscylindrical gripping portion and flared frusto-conical juncture section.The materials wrapped on the mandrel then may be placed in a clam shellstyle mold having the desired external configuration for the handle,including forms to produce a selected pattern of projections thereon.After the clam shell mold has been placed about the exterior of thehandle, the forming mandrel is removed, a pressure bladder is insertedwhere the mandrel previously had been, and pressure is applied on thebladder to force the wrapped materials outwardly against the mold. Thematerials then are allowed to cure and are removed from the mold withthe desired external configuration.

Although the handle member has been described using a plurality ofsheets of impregnated composite material, the layers may be formed bysome other method, such as a filament winding process. With a filamentwinding process, a continuous fiber, rather than a preimpregnated sheetas described above, is wrapped around a mandrel. The filament windingprocess may use a preimpregnated fiber. Alternately, the continuousfiber may run through a resin bath before it is wrapped onto themandrel. The filament winding process typically winds the fiber in ahelical path along the mandrel, making it difficult to produce a layerhaving fibers that are exactly 90 degrees relative to the longitudinalaxis of the layers. Thus the layers may include layers that are at anangle substantially 90 degrees, but not exactly at 90 degrees.

The handle member, being produced of composite material, permitsselective production to obtain a handle member of the desired weightwhile still obtaining the necessary strength and stiffness.

In an alternative preferred embodiment, the handle member can be formedof a thermoplastic material, as described above. The handle memberformed of a thermoplastic material can be produced through injectionmolding. The injection molding process includes the steps of obtaining amold having a cavity configured for the desired structure, such as thehandle member. The mold cavity is then filled with the thermoplasticmaterial under heat and pressure. The thermoplastic material can includefiber reinforcement, and/or it can be formed of a combination ofthermoplastic materials. The thermoplastic material is then allowed tocure. After curing, the structure (the handle member) is removed fromthe mold. If a fiber-reinforced thermoplastic material is used, theinjection process can be configured to orientate a significant portionthe fibers, or fiber segments, in a particular direction. As such, thehandle member formed of a thermoplastic material can be generallyanisotropic. Preferably, the handle member formed of a thermoplasticmaterial is formed to be generally isotropic (wherein the fibers, orfiber segments, are randomly configured). Alternatively, a thermoplasticor fiber-reinforced thermoplastic handle member or bat frame can beproduced through other methods, such as, for example compressionmolding.

After the handle member has been formed it is inserted through the openend 12 b of striking member 12, such that gripping portion 32 extendslongitudinally outwardly from end 12 a of the striking member. Prior toinserting the handle member a layer of adhesive is applied either to theouter surface of juncture section 34 of the handle member or the innersurface of juncture section 14 of the striking member. The strikingmember 12 and handle 30 are urged in opposite directions along thelongitudinal axis, such that the juncture section 34 of the handlemember is forced into tight engagement with the interior surface ofjuncture section 16. As this occurs, the adhesive applied between theparts is pressed into recesses 76, 78, 80 and ribs 40, or otherprojections, firmly contact, or engage, the inner surface of juncturesection 16. Excess adhesive will be allowed to flow outwardly from end30 a of the handle member, with only the selected thickness of adhesiveremaining.

It has been found that an adhesive such as Scotch-Weld™ DP-100 epoxyadhesive or PT 1000 urethane adhesive from Willamette Valley Co., ofEugene, Oreg., works well in this application. Other appropriateadhesives also may be used. In a preferred embodiment, projections 40extend outwardly from remainder portions of the outer surface of thejuncture section of the handle member in a range of 0.001 to 0.010 inch,and more preferably in a range of 0.002 to 0.005 inch and have a widthin a range of 0.125 to 0.75 inch and more preferably in a range of 0.2to 0.3 inch. The layer of adhesive will have a thickness generally equalto height of the projections and is allowed to cure and form asubstantially rigid, firm interconnection between the striking memberand the handle member. The substantially rigid interconnection betweenthe juncture sections of the striking member and handle member providedby the adhesive and direct engagement of the projections with the innersurface of the striking member permits substantially complete strikingenergy transfer between the handle member and the striking member.

After the handle member has been secured to the striking member, insert22 is inserted into the striking member, the outer end 12 b is rolledover into the configuration illustrated in FIG. 1, and stop member 50 isinserted therein. Transition member 52 (when used) is attached toprovide a smooth transition between the inner end 12 a of the strikingmember and handle 30.

Prior to, or following, assembly of the handle member and strikingmember, weighted member, or plug, 54 is inserted and secured in theproximal end portion of the handle member as shown in FIG. 1.

Weighted plug 54 is a generally cylindrical member coupled to theproximal end 30 b of the handle member 30. The weighted plug preferablyis sized to fit snugly within the proximal end 30 b of the handle member30 and preferably is affixed to the proximal end 30 b with a suitableadhesive. Alternative means for coupling the plug 54 to the proximal end30 b of the handle member 30 also are contemplated, such as, forexample, press-fit connections, fasteners, and other mechanical latchingmechanisms. The weighted plug 54 is formed of a relatively densematerial, preferably a metal. Alternatively, the weighted plug 54 can beformed of other materials, such as, for example, sand, a fluid or apolymeric material. The plug 54 is formed with a weight in the range of0.5 to 7.0 ounces, and preferably within a range of 2 to 5 ounces, and alength in the range of 1.0 to 4.0 inches.

The weighted plug 54 places additional weight, or mass, generallydirectly beneath the player's grip during swinging, thereby facilitatingthe player's ability to swing the bat and to increase his or her batspeed. The weighted plug 54 provides the player with a pivot point,which facilitates rotation of the bat about the mass or grip location ofthe player.

Additionally, the weighted plug 54 also serves to dampen, orsubstantially reduce, the shock, vibration and “sting” commonly felt bya player when hitting a ball, particularly when the ball is hit awayfrom a desired hitting region of the striking member, or the “sweetspot.” The weighted plug 54 serves as a vibration sink thatsubstantially lowers the amplitude of the vibrational energy generatedupon impact of the bat 10 with a ball at the location of the plug 54thereby reducing the vibration or shock felt by the player. In anotheralternative preferred embodiment, the plug 54 is integrally formed withthe knob 48.

The use of the weighted plug 54 is just one example of the advantagesachieved in the present invention from redistributing the weight, ormass, within the bat 10 through decoupling of the handle member 30 andthe striking member 12. When forming the handle member 30 of a compositematerial, the weight of the handle member 30 can be reduced from that ofa conventional metal handle member. This weight can then beredistributed to other locations on the bat, such as at the proximal endof the handle member 30 to improve, or tune, the performance of the bat10. In the present invention, the weighted plug 54 can be added to thebat 10 to enable the player to increase his or her bat speed, and toreduce the shock and vibration felt by the user, without excessively orunnecessarily increasing the weight of the bat 10. In anotheralternative preferred embodiment, weight can be redistributed to thestriking member 12.

The method described herein and the bat produced provide a bat which hasimproved striking capabilities. Such improved striking capabilities areprovided by the structural characteristics of the bat. In one instanceincreased bat swing speed is allowed by producing a bat with a handlewhich is lighter than would be the case if it were made of the samematerial or in a manner similar to the striking portion of the bat. Thisreduction in weight of the handle in relation to the striking portionand providing a substantially rigid interconnection between the twopermits increased bat speed and substantially complete striking energytransfer between the striking member and the handle member. Further itprovides desirable weight distribution in the bat with the greatesteffective mass in the striking region and lower effective mass in thehandle.

It also has been found that the slugging, or hitting, characteristics ofthe bat may be varied by mating various composite handle members withstriking members of different materials or configurations, with asubstantially rigid interconnection therebetween. Thus different modelsof bats may be produced, tuned to selected requirements.

By providing a bat constructed with an independently produced strikingmember and handle member which are rigidly interconnected at a junctureregion, bats may be made with numerous selected functionalcharacteristics. The striking member may be made of materials whichprovide optimum ball striking effectiveness, while the handle member maybe constructed in such a fashion that is allows the batter to impart themaximum possible force from the batter's hands to the bat and to producethe greatest swing speed. The handle member may be laid up from avariety of composite materials with selected thicknesses, orientations,and positions within the handle member to produce desired strength,weight, stiffness, etc., in the overall handle or even within selectedregions of the handle.

Explaining further, selected regions of the handle may have a greater orlesser number of layers of composite material than other regions, thethicknesses or structural materials within the layers may vary atdifferent regions of the handle member, and other characteristics may bevaried through selected lay up of materials in the handle member duringproduction.

As an example of desirable differences in handle members which may beformed, it has been found that certain bats, such as for softball use,will work better with a stiffer handle member, whereas for baseball amore flexible, or less stiff, handle member is preferable.

In one preferred embodiment, the handle member 30 of the bat 10 can beformed of a thermoplastic material, a fiber reinforced thermoplastic andcombinations thereof. A thermoplastic material becomes soft and moldablewhen heated and changes back to solid when allowed to cool. Examples ofthermoplastics are nylon, urethane, ABS, polyvinylchloride,polyethylene, polypropylene acetal, acrylic, cellulose acetate, nylon,polystyrene, vinyl, and combinations thereof. Thermoplastic materialsthat are flexible even when cool are known as thermoplastic elastomersor TPEs. When thermoplastic materials are heated, the linked chains ofmolecules can move relative to each other, allowing the mass to flowinto a different shape. Cooling prevents further flow. Although theheating/cooling cycle can be repeated, recycling reduces mechanicalproperties and appearance.

In contrast to thermoplastic materials, thermoset materials or plasticsexperience a chemical change during processing and become hard solids.Although the structures of thermoset materials are similar to those ofthermoplastic materials, processing develops permanent cross-linksbetween adjacent molecules, forming complex networks that preventrelative movement between the chains at any temperature. Examples ofthermoset materials include amino, epoxy, phenolic, and unsaturatedpolyesters. Many rubbers that are processed by vulcanizing, such asbutyl, latex, neoprene, nitrile, polyurethane, and silicone, also areclassified as thermosets. Heating a thermoset degrades the material sothat it cannot be reprocessed satisfactorily.

The handle member 30 can be formed separately from, or integrally with,the striking member 12. The fiber reinforced thermoplastic material caninclude fibers formed of glass, fiberglass, aramid, carbon, Kevlar®,high molecular weight polyethylene in strand form, or other conventionalfiber materials. Preferably, a highly damped thermoplastic orfiber-reinforced thermoplastic material is used. The highly dampedthermoplastic or fiber-reinforced thermoplastic retains some flexibilitywhich allows for the handle member to exhibit the low resistance tobending values. In one example, the highly damped thermoplastic materialused to form the handle member can be an injection molded urethaneincluding approximately 40-50 percent glass fibers (handle membersTP306, TP606 and TP706 of Table 3 include this construction). In otherembodiments, other highly damped thermoplastic materials, and otherpercentages of the fiber material and/or other fiber material can beused. In another example, nylon can be used as the thermoplasticmaterial with approximately 10 percent glass fibers. In this example,the thermoplastic nylon material exhibits lower damping characteristics.

Many embodiments of the present application, including bats formed withthermoplastic handles, provide the benefit of generally having lowresistance to bending values, such as the ranges listed above including800-900 lbs/in, 700-800 lbs/in, 600-700 lbs/in, 500-600 lbs/in, 400-500lbs/in, 300-400 lbs/in, 200-300 lbs/in, 100-200 lbs/in and 10-100lbs/in. The thermoplastic material and/or fiber-reinforced thermoplasticmaterial can also provide exceptional frequency and dampingcharacteristics, particularly in the first and second bending modes ofvibration. The first and second bending modes are generally responsiblefor the feel or sensations felt by batters, particularly when contactingthe ball away from the sweet spot. A modal analysis test can beperformed to measure the damping ratio and frequency characteristics,including the first and second bending modes. It is important to notethat not all thermoplastic materials or fiber-reinforced materialsprovide a high level of damping. Many embodiments of ball bats formedwith thermoplastic, or fiber-reinforced thermoplastic, handle membersare configured for organized competitive play.

Bats including a handle member 30 formed of a highly dampedthermoplastic material, a highly damped fiber reinforced thermoplasticmaterial, or other highly damped materials, are capable of providing thebatter with exceptional feel, while still maintaining exceptionalhitting or power transfer performance. Further, such highly damped batsprovide the batter with a more controlled feel. During use, manyconventional bats exhibit excessive vibration, oscillation and/ormodulation following impact with the ball. Such movement can leave abatter with a feeling of having less control over the movement of thebat because the batter can receive a sensation indicating that thebarrel is moving outside of his or her control. Such sensations canreduce a player's confidence level at the plate and his or herconfidence level in controlling the position of the bat during his orher swing. The highly damped bats of the present applicationsignificantly reduce such oscillation, vibration and movement of the batafter impact thereby providing the batter with a greater sense ofcontrol. One unexpected result of the embodiments of the presentapplication having bat handles formed of a highly damped material isthat damping typically connotes a reduction or absorption of energy. Inthe present invention, the damping can greatly improve the feel andcontrol of the bat without negatively affecting the bat's performancefor all levels of play, including organized, competitive play.

In one preferred embodiment, the handle member 30 is formed of athermoplastic material, and/or fiber-reinforced thermoplastic material,wherein the damping ratio in the first bending mode of vibration isgreater than or equal to 0.010, when tested in accordance with the modalanalysis test described below. The first bending mode frequencyassociated with first bending mode damping ratio is less than or equalto 320 Hz and greater than or equal to 50 Hz. In one preferredembodiment, the first bending mode frequency is less than or equal to280 Hz and greater than or equal to 100 Hz. In another preferredembodiment, the first bending mode frequency is less than or equal to260 Hz and greater than or equal to 140 Hz. The damping ratio in thesecond bending mode of vibration is also equal to or greater 0.010, whentested in accordance with the modal analysis test described below. Thesecond bending mode frequency associated with second bending modedamping ratio is less than or equal to 1000 Hz and greater than or equalto 450 Hz. In one preferred embodiment, the second bending modefrequency is less than or equal to 930 Hz and greater than or equal to500 Hz. In another preferred embodiment, the second bending modefrequency is less than or equal to 710 Hz and greater than or equal to500 Hz. In an alternative preferred embodiments, the handle member canbe formed of a thermoplastic material or fiber-reinforced thermoplasticmaterial exhibiting a damping ratio in the first and/or second modes ofvibration of greater than or equal to 0.015, 0.020 or 0.022, also withinthe frequency ranges described above. Each one of these damping ratiovalues can result in a ball bat that meets a particular applicationand/or a particular player's needs. In other alternative preferredembodiments, a non-thermoplastic material can be used such as, forexample, a thermoset material, provided that the handle of the bat has adamping ratio in the first and second bending modes of at least 0.010.

Referring to FIG. 15, one method of performing a modal analysis test ona handle member 30 of a bat is illustrated. Although FIG. 15 illustratesa handle member 30 supported by the modal test assembly 200, the modaltest assembly 200 can also be used to test an entire bat including, forexample, a bat having a one-piece bat frame. The modal analysis testassembly 200 includes a base 202 for supporting first and second supportassemblies 204 and 206 and the handle member 30. The base 202 can be anystructure that properly supports the first and second supportassemblies. The first and second support assemblies 204 and 206 eachinclude a pair of spaced apart rigid supports and a flexible memberspanning between the pair of supports. The flexible member can be arubber band. The first and second support assemblies 204 and 206 suspendthe test object, such as the handle member 30, in a substantiallyhorizontal position and provide a substantially “free-free” boundarycondition.

The modal analysis test assembly 200 further includes an accelerometer208, a power conditioner 210, a PC data acquisition card, dataacquisition software, modal analysis software, memory, and an impulseforce hammer 212. The accelerometer 208 is removably attached to thehandle member 30 and operably coupled to the power conditioner 210. Thepower conditioner 210 is operably connected to the PC data acquisitioncard. The PC data acquisition card can be a Model DAP4000a/112 fromMicrostar Laboratories of Bellevue, Wash. or equivalent. Theaccelerometer 208 has a measurement range of +/−500 g and can be a Model352C22 produced by PCB Piezotronics™ of Depew, N.Y., or an equivalent.The power conditioner can be a Type 5134A produced by Kistler InstrumentCorporation of Amhurst, N.Y. or equivalent. The PC data acquisition cardincludes the data acquisition software and is capable of processing atleast 400,000 samples per second per channel. The data acquisitionsoftware can be LabView™ software from National Instruments of Austin,Tex., or equivalent. The impulse force hammer 212 is operably coupled tothe power conditioner 210 and is used to generate a force pulse throughimpact of the hammer to the handle member 30. The impulse test hammercan be a Model 9722A-2000 produced by Kistler Instrument Corporation ofAmhurst, N.Y. or equivalent. The impulse force hammer 212 includes aload cell for measuring the load applied to the bat, or handle member,during impact.

The modal analysis test includes determining the natural frequencies ofvibration of the bat and the associated damping at each of thesefrequencies. The mode shape of the bat or the handle member for each ofthese natural frequencies can also be determined. Preferably, allvibration damping devices are removed from the test object. In batswherein the handle member is formed separately from the striking member,the handle member is preferably tested apart from the striking member.Further, some bats include added weights placed within the inner bore ofthe handle member. These added weights are also preferably removed. Theknob of the bat handle is also typically removed; however, the test maybe performed with the knob attached to the handle member. The testobject (the bat handle or the bat as a whole) is initially marked at oneinch increments along its longitudinal axis. The test object issuspended on the flexible members of the first and second supportassemblies 204 and 206 in a substantially horizontal position. Theaccelerometer 208, operably engaged to the power conditioner 210, isplaced at a location between two of the one inch increments on the testobject. The impulse force hammer 212 is then used to sequentially impact(excite) the test object at the one inch increment markings on the batwith sufficient time intervals between impacts to avoid overlappingresponse signals. The excitation of the test object at numerouslocations allows for the mode shape of the test object to be accuratelyapproximated. If the accelerometer is positioned at a node, theaccelerometer requires repositioning to a new location and the test isrepeated. The PC data acquisition card processes the signal from theload cell of the impulse force hammer 212 along with the response dataof the accelerometer 208. The impulse force hammer impact data andaccelerometer response data for each individual impact location isstored in a data file.

A modal analysis computer program utilizing Matlab® software from TheMathWorks, Inc. of Natick, Mass. can be used. Alternatively, modalanalysis programming can be performed using StarModel™ software fromSpectral Dynamics of San Jose, Calif. or equivalent. A modal analysis isperformed on the data points using the load and excitation data fromeach impact location with the handle or bat to determine the naturalfrequencies of the test object, the damping ratios associated with eachnatural frequency and the mode shape associated with each naturalfrequency. Test objects (a bat handle or a bat frame) contain manynatural frequencies and each frequency has an associated damping value.The natural frequencies and damping values with each of thesefrequencies can be determined through modal analysis.

The frequency response of the test object is obtained by taking the fastFourier transformation (“fft”) of the measured input force from theimpulse force hammer 212 and the resulting acceleration of the testobject obtained from the accelerometer 208. The fft converts theresponse of the test object from the time domain (the excitation of thetest object over time in response to the impact by the hammer) into thefrequency domain where the signal is divided into discrete magnitude andfrequency components. The output frequency response is normalized bydividing by the input frequency response. The normalization of theoutput frequency response accounts for the variability of the inputforce (of the impulse force hammer) from trial to trial (impact toimpact). From the normalized output frequency response, frequencyresponse peaks can be identified. The identification of the frequencyresponse peaks can be performed using software, manually from visuallyinspecting graphical information or from reading peak values from a datafile. FIG. 16 illustrates an example of bat excitation data in thefrequency domain from an impact point location 17. Once the frequencyresponse peaks are located, the calculation of the natural frequenciesand damping ratios can be carried out using an inverse line fit methodor a circle fit method. The inverse line fit method is preferred. Acalculated modal natural frequency and damping ratio value is determinedfor each of the impulse hammer impact points along the test object. Thenatural frequencies and damping ratios remain generally constant nomatter where the test object is excited, unless the excitation occurs ata node (zero value). The frequency response for each data set can becombined to calculate the mode shape of the test object. FIGS. 17 and 18illustrate examples of 1^(st) and 2^(nd) bending mode shapes of the testobject, respectively. The frequency and damping are also illustrated foreach mode.

Modal analysis of handle members illustrates the increased damping atthe 1^(st) and 2^(nd) bending modes, and the reduced 1^(st) and 2^(nd)bending mode vibration levels, of bats formed with highly dampedthermoplastic material. Table 3 provides a listing of frequency anddamping ratios in the 1^(st) and 2^(nd) bending modes for severaldifferent handle members of bats. The first grouping lists threeseparate handle members formed of a highly damped fiber-reinforcedthermoplastic material. This first grouping illustrates the high dampingratio values and low frequencies obtained through the use of highlydamped thermoplastic materials. These handle members when assembled inbats provide the batter with an exceptional feel and optimal hittingand/or slugging performance. The negative vibration, oscillation andshock often experienced by batters during off-center impacts with a ball(away from the sweet spot of the bat) are significantly damped andreduced enabling the user to feel more confident and focused at theplate and providing the user with a greater sense of control over thebat. Table 3 also lists, in a second grouping, the bending modefrequency and damping ratios of two handle members formed of less dampedthermoplastic materials. Table 3 further lists a third grouping ofhandle members of bats formed of a thermoset composite material.Finally, a fourth grouping of Table 3 lists bats having handle membersformed of metal. Some of the bats in the third and fourth groupingsinclude one-piece bat frames. Accordingly, in order to test the handlemember only, the one-piece bat frames were cut or sectioned in atransverse direction at a location where the tapered section of the bat(or handle member) reached a predetermined outside diameter (preferably,an outside diameter within the range of 1.9 to 2.25 inches). TABLE 31^(ST) & 2^(ND) BENDING MODE FREQUENCY AND DAMPING RATIO VALUES OFHANDLE MEMBERS 1^(st) Bending 2^(nd) Bending Mode Mode Handle MemberDamping Damping Description Frequency Ratio Frequency Ratio TP306 239.240.022515 696.91 0.024787 TP606 253.07 0.027664 702.14 0.024580 TP706229.41 0.023544 638.18 0.026412 TP506 (with knob) 166.38 0.004218 521.380.005868 TP506 212.99 0.005570 624.27 0.006543 Easton ® Stealth ™ 346.540.005712 970.50 0.003789 DeMarini ® F2 ™ 313.97 0.003163 919.88 0.003821Miken ® Ultra ™ 648.28 0.002539 1857.20 0.004556 Mizuno ® Techfire ™597.28 0.001366 1676.70 0.002357 DeMarini ® 238.82 0.002654 723.210.001571 Vexxum ™-3 Easton ® (metal) 475.97 0.000444 1366.90 0.000428Worth ® (metal) 396.65 0.000391 1159.50 0.000099 DeMarini ® (metal)461.10 0.000335 1317.50 0.000142Easton ® is a registered trademark of Jas. D. Easton, Inc. Worth ® is aregistered trademark of Worth, Inc. Mizuno ® is a registered trademarkof Mizuno Corp.

Table 3 illustrates that the handle members formed of a highly dampedfiber-reinforced thermoplastic material (the first grouping) havedamping ratios in the first and second bending modes that are an orderof magnitude higher than handle members formed without thermoplasticmaterial and handle members formed of less damped fiber-reinforcedthermoplastic material. The handle members of the first group provide asignificantly higher level of damping than the other bat handle memberstested. Further, the handle members formed of a thermoplastic materialexhibit first and second bending mode frequencies that are lower thanthe first and second bending mode frequencies of handle members formedof non-thermoplastic materials.

All the bats listed in Table 3 are designed for use in softball orbaseball. The additional handle weight and the isolation union wereremoved from handle member of the Easton® Stealth™ bat prior to testing.The isolation union was also removed from the Easton® metal bat prior totesting. A handle weight was also removed from the Miken® Ultra™ batprior to testing. The handle portions were cut from the Miken® Ultra™bat, the Mizuno® Techfire™ bat and the Worth® metal bat prior totesting.

With the structure and method for producing such set out herein, a batmay be optimized for the selected usage by selection of materials andlay up for the various components of the bat.

While there have been illustrated and described preferred embodiments ofthe present invention, it should be appreciated that numerous changesand modifications may occur to those skilled in the art and it isintended in the appended claims to cover all of those changes andmodifications which fall within the spirit and scope of the presentinvention.

1. A bat capable of being tested with a modal analysis test assemblyhaving first and second supports assemblies, the bat comprising: anelongate tubular striking member having a distal end, a proximal end,and a striking region intermediate the distal and proximal ends; and aseparate handle member having a distal end and a proximal end, thehandle member coupled to the striking member, the handle member beingformed of a thermoplastic or fiber-reinforced thermoplastic material,the handle member having a damping ratio in the first bending mode ofgreater than or equal to 0.010 in a modal analysis test wherein thehandle member is supported by the first support assembly adjacent thedistal end of the handle member and the second support assembly adjacentthe proximal end of the handle member, the bat configured for organized,competitive play.
 2. The bat of claim 1, wherein the damping ratio ofthe handle member in the first bending mode is greater than or equal to0.015.
 3. The bat of claim 1, wherein the damping ratio of the handlemember in the first bending mode is greater than or equal to 0.020. 4.The bat of claim 1, wherein the damping ratio of the handle member inthe first bending mode is greater than or equal to 0.022.
 5. The bat ofclaim 1, wherein the handle member has a first bending mode frequency ofgreater than or equal to 50 Hz and less than or equal to 320 Hz.
 6. Thebat of claim 1, wherein the handle member has a first bending modefrequency of greater than or equal to 100 Hz and less than or equal to280 Hz.
 7. The bat of claim 1, wherein the handle member has a firstbending mode frequency of greater than or equal to 140 Hz and less thanor equal to 260 Hz.
 8. The bat of claim 1, wherein the handle member isconfigured for testing in a three-point bend stiffness test devicehaving first and second supports, and wherein the handle member has aresistance to bending along a longitudinal axis in the range of 10-850lbs/in a three-point bend stiffness test wherein the handle member istransversely supported in a first direction by the first and secondsupports spaced apart a selected distance, with the first supportadjacent the distal end of the handle member and the second supportadjacent the proximal end of the handle member, and the handle member istransversely loaded in a second direction, opposite the first direction,at a location on the handle member in a region between 30% and 40% ofthe selected distance from the distal end of the handle member.
 9. Thebat of claim 8, wherein the handle member has a resistance to bendingalong the longitudinal axis in the range of 700-800 lbs/in.
 10. The batof claim 8, wherein the handle member has a resistance to bending alongthe longitudinal axis in the range of 600-700 lbs/in.
 11. The bat ofclaim 8, wherein the handle member has a resistance to bending along thelongitudinal axis in the range of 500-600 lbs/in.
 12. The bat of claim8, wherein the handle member has a resistance to bending along thelongitudinal axis in the range of 400-500 lbs/in.
 13. The bat of claim8, wherein the handle member has a resistance to bending along thelongitudinal axis in the range of 300-400 lbs/in.
 14. The bat of claim8, wherein the handle member has a resistance to bending along thelongitudinal axis in the range of 200-300 lbs/in.
 15. The bat of claim8, wherein the handle member has a resistance to bending along thelongitudinal axis in the range of 100-200 lbs/in.
 16. The bat of claim8, wherein the handle member has a resistance to bending along thelongitudinal axis in the range of 10-100 lbs/in.
 17. The bat of claim 1,wherein the handle member comprises fiber-reinforced urethane, andwherein the fibers are selected from the group consisting of glass,aramid, carbon, Kevlar®, polyethylene and combinations thereof.
 18. Thebat of claim 1, wherein the thermoplastic material of the handle membercomprises nylon, polyester, ABS, polyvinylchloride, polyethylene,polypropylene, acetal, acrylic, cellulose acetate, polystyrene,vulcanized rubber, latex, neoprene, nitrile, silicone, and combinationsthereof.
 19. The bat of claim 1, wherein the handle member is firmlyjoined adjacent its distal end to the proximal end of the strikingmember to provide a rigid interconnection therebetween to permitsubstantially complete striking energy transfer between the handlemember and the striking member.
 20. The bat of claim 1, wherein the bathas an overall first length, wherein the striking member has a secondlength, wherein the handle member has a third length, and wherein thesecond and third lengths are each shorter than the first length.
 21. Thebat of claim 1, wherein the striking member is formed from a materialselected from the group consisting of a metal, wood, a fiber compositematerial, and a non-metallic material.
 22. The bat of claim 1, whichfurther comprises a second tubular member concentric with the strikingregion of the striking member.
 23. The bat of claim 22, wherein thesecond tubular member is configured to move independently of thestriking member upon impact with a ball.
 24. A bat capable of beingtested with a modal analysis test assembly having first and secondsupports assemblies, the bat comprising: a non-wooden, one-piece batframe including a distal end, a proximal end, an elongate tubularstriking portion and a handle portion, the handle portion including atapered region, the handle portion being formed of a thermoplastic orfiber-reinforced thermoplastic material, the handle portion having adamping ratio in the first bending mode of greater than or equal to0.010 in a modal analysis test wherein the handle portion is cut awayfrom the striking portion at a first location where the tapered regionof the handle portion has an outer diameter within the range of 1.9 to2.25 inches and wherein the handle portion is supported by the firstsupport assembly adjacent the proximal end of the bat frame and thesecond support assembly at the tapered region of the handle portion, thebat configured for organized, competitive play.
 25. The bat of claim 24,wherein the damping ratio of the handle portion in the first bendingmode is greater than or equal to 0.015.
 26. The bat of claim 24, whereinthe damping ratio of the handle portion in the first bending mode isgreater than or equal to 0.020.
 27. The bat of claim 24, wherein thedamping ratio of the handle portion in the first bending mode is greaterthan or equal to 0.022.
 28. The bat of claim 24, wherein the handleportion has a first bending mode frequency of greater than or equal to50 Hz and less than or equal to 320 Hz.
 29. The bat of claim 24, whereinthe handle portion has a first bending mode frequency of greater than orequal to 100 Hz and less than or equal to 280 Hz.
 30. The bat of claim24, wherein the handle portion has a first bending mode frequency ofgreater than or equal to 140 Hz and less than or equal to 260 Hz. 31.The bat of claim 24, wherein the handle portion is configured fortesting in a three-point bend stiffness test device having first andsecond supports, and wherein the handle portion has a resistance tobending along a longitudinal axis in the range of 10-850 lbs/in athree-point bend stiffness test wherein the handle portion istransversely supported in a first direction by the first and secondsupports spaced apart a selected distance, with the first supportadjacent the distal end of the handle portion and the second supportadjacent the proximal end of the handle portion, and the handle portionis transversely loaded in a second direction, opposite the firstdirection, at a location on the handle portion in a region between 30%and 40% of the selected distance from the distal end of the handleportion.
 32. The bat of claim 31, wherein the handle portion has aresistance to bending along the longitudinal axis in the range of700-800 lbs/in.
 33. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of600-700 lbs/in.
 34. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of500-600 lbs/in.
 35. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of400-500 lbs/in.
 36. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of300-400 lbs/in.
 37. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of200-300 lbs/in.
 38. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of100-200 lbs/in.
 39. The bat of claim 31, wherein the handle portion hasa resistance to bending along the longitudinal axis in the range of10-100 lbs/in.
 40. The bat of claim 24, wherein the handle portioncomprises fiber-reinforced urethane, and wherein the fibers are selectedfrom the group consisting of glass, aramid, carbon, Kevlar®,polyethylene and combinations thereof.
 41. The bat of claim 24, whereinthe thermoplastic material of the handle portion comprises nylon,polyester, ABS, polyvinylchloride, polyethylene, polypropylene, acetal,acrylic, cellulose acetate, polystyrene, vulcanized rubber, latex,neoprene, nitrile, silicone, and combinations thereof.
 42. The bat ofclaim 24, wherein the handle portion is firmly joined adjacent itsdistal end to the proximal end of the striking member to provide a rigidinterconnection therebetween to permit substantially complete strikingenergy transfer between the handle portion and the striking member. 43.The bat of claim 24, wherein the bat has an overall first length,wherein the striking member has a second length, wherein the handleportion has a third length, and wherein the second and third lengths areeach shorter than the first length.
 44. The bat of claim 24, wherein thestriking member is formed from a material selected from the groupconsisting of a metal, wood, a fiber composite material, and anon-metallic material.
 45. The bat of claim 24, which further comprisesa second tubular member concentric with the striking region of thestriking member.
 46. The bat of claim 45, wherein the second tubularmember is configured to move independently of the striking member uponimpact with a ball.
 47. A bat capable of being tested with a modalanalysis test assembly having first and second supports assemblies andin a three point bend stiffness test device having first and secondsupports, the bat comprising: an elongate tubular striking member havinga distal end, a proximal end, and a striking region intermediate thedistal and proximal ends; and a separate handle member having a distalend and a proximal end, the handle member coupled to the strikingmember, the handle member having first and second damping ratios in thefirst and second bending modes, respectively, of greater than or equalto 0.020 in a modal analysis test wherein the handle member is supportedby the first support assembly adjacent the distal end of the handlemember and the second support assembly adjacent the proximal end of thehandle member, the handle member having a first bending mode frequencyof greater than or equal to 100 Hz and less than or equal to 280, and asecond bending mode frequency of greater than or equal to 450 and lessthan or equal to 1000 Hz, and the handle member having a resistance tobending along a longitudinal axis in the range of 10-850 lbs/in athree-point bend stiffness test wherein the handle member istransversely supported in a first direction by the first and secondsupports spaced apart a selected distance, with the first supportadjacent the distal end of the handle member and the second supportadjacent the proximal end of the handle member, and the handle member istransversely loaded in a second direction, opposite the first direction,at a location on the handle member in a region between 30% and 40% ofthe selected distance from the distal end of the handle member. the batconfigured for organized, competitive play.
 48. The bat of claim 47,wherein the first and second damping ratios of the handle member in thefirst and second bending modes, respectively, are each greater than orequal to 0.022.
 49. The bat of claim 47, wherein the handle portion isformed of a thermoplastic or fiber-reinforced thermoplastic material.50. The bat of claim 47, wherein the handle member comprisesfiber-reinforced urethane, and wherein the fibers are selected from thegroup consisting of glass, aramid, carbon, Kevlar®, polyethylene andcombinations thereof.
 51. The bat of claim 47, wherein the handle memberis firmly joined adjacent its distal end to the proximal end of thestriking member to provide a rigid interconnection therebetween topermit substantially complete striking energy transfer between thehandle member and the striking member.
 52. The bat of claim 47, whereinthe bat has an overall first length, wherein the striking member has asecond length, wherein the handle member has a third length, and whereinthe second and third lengths are each shorter than the first length.